While many ecosystems involve fire in some form, few are as dependent on fire as tallgrass prairies. Biomass is able to quickly accumulate each year in prairies as old leaves die in autumn and fall onto the ground. This biomass which can build up over the years, covering the soil, makes it difficult for new shoots to become established in the spring. The soil being covered reduces sunlight and keeps the soil cooler, causing a delay in plant growth.¹ In that regard, fire is a single solution to multiple issues that must be dealt with so the ecosystem can be sustained. Fire clears away accumulated biomass, and the nutrients trapped in plants that have yet to decay are released back into the soil. The soil being exposed following a burn allows for the soil to warm and new shoots to establish with less difficulty.

Additionally, many prairie plants are adapted to fire and thrive under a regular fire regime. Prairie plants have long and extensive root systems that allow the plant to survive and regrow quickly after fires. In fact, below-ground biomass for prairies can be as much as two to four times higher than aboveground biomass.² This means that while many native plants can survive and even benefit from fires, invasive or harmful species populations who are not fire-adapted will be reduced or eliminated. Fires are also critical for reducing the number of woody species in prairies. Since many prairie plants thrive under sunny conditions, trees that grow and develop a canopy will quickly shade out prairie species. Since trees invest so much energy into growing their trunks and branches, fire is a good way to control encroaching woody species.

Site Preparation

• Allow fuel to accumulate

• Establish burn breaks to limit the spread of fire

• Movement of coarse and volatile fuels away from the burn break

  • Coarse fuels are woody materials that can burn for long periods such as dead trees or brush piles

  • Volatile fuels consist of plant species that contain higher levels of compounds (resins, oils, waxes) that cause more intense burns³

Weather - the weather can make or break a burn, and the ideal conditions for a burn may vary based on location, fuel, season, etc.

• Humidity

• Air temperature

• Wind speed and direction

Crew - the size of fire crew needed depends on both the size of the fire and the experience of the members

Ignition

• Burn breaks, while essential, are often not wide enough to stop head fires, or the side of the fire that is spreading the fastest

  • This is why backfires (fire going into the wind) or strip head fires (head fires lit with only a few feet of fuel ahead of them) are lit along burn breaks⁴

  • This creates blackened areas that essentially widen the burn break by creating more area where fire cannot catch

Clean-up

• It is not safe to leave a completed burn while there is still smoke or flame

• Smoking and remaining small flames should be extinguished

• Any patches of unburned vegetation should be examined for fire